SUCCINEA. 429 



eighths the length of the shell ; aperture two thirds the length of the shell, 

 strictly ovate, one tliird longer than broad ; columella arcuate, but not folded, 

 a tliiu white callus of considerable extent covering it. Length, 6| mill. ; great- 

 est lateral diameter 8J, least 2| mill. 



Succinca Orcgonensis, Lea, Proc. Am. Phil. Soc, 11. 32 (1841) ; Trana., IX. 5 ; 

 Obs., IV. 5 (1844). — Pfeiffer, Mon. llel. Viv., II. 523. — Binney, Terr. 

 Moll., II. 77, PI. LXVII. Fig. 2. — W. G. Binney, Terr. Moll., IV. 6 ; L. & 

 Fr.-W. Sh., I. 270 (1869). — Tryon, Am. Journ. Conch., II. 235 (1866). 



Succinea Gahhii, Tryon, Am. Journ. Conch., II. 234, PI. II. Fig. 14 (1866). 



Oregon and California, in the Pacific Province. 



Animal unknown. 



Compared with S. aurea, it is much smaller, and combines red in its colora- 

 tion ; the aperture is more rounded at base, so as to be more broadly ovate ; 

 the whorls are also more rounded. Grains of sand adhere to its surface, much 

 as in the young of S. avarOy but no epidermal hairs have been noticed. 



Succinea efifuaa, Shuttleworth. 



Shell depressed-oval, very thin, transparent, and shining, lightly striated, 

 grayish horn-colored ; spire remarkably short, acute ; whorls 2|^, the 

 last one very much the largest, depressed, equalling five sixths the '°' 

 length of the shell ; columella scarcely rounded and hardly receding ; 

 aperture very large, oblique, and oval ; peristome simple, regularly 

 rounding. Length 12, diameter 7 mill. ; length of the aperture 10, 

 breadth 6 mill. ^ ,^„^^ 



Succinea effusa, Shuttleworth, MSS. — Pfeiffer, Mon. Hel. Viv., 



III. 17 ; in Chemnitz, ed. 2, 42, PL IV. Figs. 18-20(1854). —W. G. Binney, 

 Terr. MolL, IV. 41, PL LXXX. Fig. 12 ; L. & Fr.-W. Sh., I. 270 (1869).— 

 Tryon, Am. Journ. Conch., II. 231 (1866). 



East Florida ; Spring Garden, Lake Florida : in the Florida Subregion. 



It is readily distinguished from the other American species by the propor- 

 tionally short spire, the very large body-whorl, and expanded aperture. 



Jaw strongly arched ; ends blunt, attenuated ; cutting edge deeply concave 

 and furnished with a prominent pointed beak ; anterior surface with vertical 

 and horizontal striae, but no grooves or rib-like processes; accessory plate 

 large, subquadrate. 



Lingual membrane (PL X. Fig. N) has 15 — 1—15 teeth, with 10 perfect 

 laterals. 



Succinea Salleana, Pfeiffer. 



Shell depressed-ovate, very thin, delicately striated, irregularly marked with 

 impressed spiral lines, pellucid, shining, whitish horn-colored ; spire very short, 

 subtuberculous ; whorls 2^, the penultimate convex, the last exceeding three 

 fourths the length of the shell ; columella with a slight callus, strictly receding ; 



